Study of the pull-out test of multifilament yarns embedded in cementitious matrix

Slama, Anne-Claire; Gallias, Jean-Louis; Fiorio, Bruno

doi:10.1177/0021998320946368

Cited by 6 publications

(6 citation statements)

References 38 publications

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“…It is not the case for the matrices with cement and calcareous filler. For those matrices, the main parameters influencing the results are the fluidity of the matrix and the embedded length of the samples (see Slama et al., 7 ). It was explained by the fact that a higher embedded length and a higher fluidity both lead to more filaments/matrix bonds, and so higher P max values.…”

Section: Resultsmentioning

confidence: 99%

“…For matrices with 100% of cement, it was found that one of the parameters influencing the P max values is the matrix mechanical properties, and especially its compres-F I G U R E 5 P max according to the number of fully impregnated filaments, error bars are the standard deviation sive strength (see Slama et al, 7 ). It was explained by the fact that, for those strong matrices, the filament/matrix bond strength is high and it determines the results.…”

Section: Resultsmentioning

confidence: 99%

“…The crosshead displacement and the pullout load were registered. All those steps are presented in Slama et al 7 ,. with images.…”

Section: Methodsmentioning

confidence: 99%

“…All the matrices considered in this study, with their label, composition, rheological and mechanical properties are shown in Table 1. Details can be found in Slama et al 7 .…”

Section: Yarn and Matricesmentioning

confidence: 99%

“…After pullout test, the samples underwent a double resin impregnation process. All those steps and details of this technique are presented in Slama et al 7 , with images of the different steps. First, an epoxy resin with a fluorochrome marker from Carl Roth company, rhodamine, was deposited with a syringe into the embedded yarn at the yarn/mortar interface (complete penetration of the resin was ensured by checking that the resin reaches the opposite side of the sample, at the end of the embedded length, on the sawed surface).…”

Section: Double Impregnation and Confocal Microscopymentioning

confidence: 99%

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A quantitative study of the influence of cement matrix impregnation on yarn pullout strength using combined confocal microscopy and double resin impregnation

Slama

Agniel

Gallias

et al. 2022

Journal of Microscopy

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The complex impregnation of a multifilament yarn by a cementitious matrix leads to a difficult prediction of the mechanical behaviour of textile reinforced concrete and its less spread use than steel‐reinforced concrete. To solve this problem, several models were established but they are not based on direct observations of the embedded yarn or quantification of its impregnation. In order to improve those models, a double resin impregnation process followed by confocal microscopy was set up, after pullout test was performed on each sample. Several parameters were then computed from the obtained images, which enables to quantify the impregnation of the yarn for each sample and to compare it with the pullout mechanical results. The number of fully impregnated filaments is found to be the crucial point to explain the pullout maximum load. The type of failure is also defined using those same parameters, computed along the embedded length, and it was found that the shape of the extracted volume of yarn is cylindrical and so the failure of the filaments is not telescopic. A pre‐existing model was then improved, considering all those conclusions obtained by microscopic observations, and a good match between the numerical and the experimental results was found. Multifilament yarns are a continuous and flexible textile structure composed of hundreds of filaments that are maintain together using a chemical product called sizing. Those multifilament yarns can be used to reinforce mortar or concrete, like steel in steel‐reinforced concrete. The performances of those types of composites depend strongly on the strength of the reinforcement/mortar bond. In case of textile /mortar composite, this bond depends on the level of penetration of the mortar into the yarn, so the impregnation of the yarn by the mortar. Since they are both very heterogeneous material, this impregnation is random and incomplete. Consequently, it is very difficult to predict the strength of this bond and so, the strength of the yarn/mortar composite. As a result, this type of composite cannot be widely used. Some models were established to predict the strength of those composite; however, they are not based on direct observation of the textile/mortar bond. To improve those models, a new visualisation method of the impregnation of the yarn by the mortar was set up. A double moulding of the impregnated yarn by the mortar was manufactured, using resins and two different fluorescent dyes, after underwent a mechanical test of pulling out the yarn from the mortar (pullout test). First, a resin with a red fluorescent dye was used for the moulding of the yarn shortly after the test, and, second, after dissolution of the mortar around the yarn in acid, a resin with a green fluorescent dye. A number of cross sections of the yarn is observed using a microscope that detects those two dyes and the obtained images are analysed allowing a clear differentiation, location and counting of fully impregnated filaments of the yarn by the mortar and those partially or n...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…The crosshead displacement and the pullout load were registered. All those steps are presented in Slama et al 7 ,. with images.…”

Section: Methodsmentioning

confidence: 99%

“…All the matrices considered in this study, with their label, composition, rheological and mechanical properties are shown in Table 1. Details can be found in Slama et al 7 .…”

Section: Yarn and Matricesmentioning

confidence: 99%

Section: Double Impregnation and Confocal Microscopymentioning

confidence: 99%

See 3 more Smart Citations